If you keep the canister warm, I understand you should be OK.
True, but the Devil's in the details as they say. How
to keep the canister warm in some pretty cold weather (below 15F/-9C per the original post). There are tricks, but it gets increasingly tough. Of course, on the other hand, tricks that would be tantamount to applying for a Darwin Award in warmer weather start to make sense in cold weather of the type we're describing.
The original poster's idea of just taking his PR out and trying it is a good one. He's got a few tips and tricks, so he may be able to get her to go.